Granted U.S. Pat. No. 8,157,742 discloses a system for planning a treatment of a patient. The system comprises a computer system configured to receive patient-specific data regarding a geometry of an anatomical structure of the patient, to create a three-dimensional model representing at least a portion of the anatomical structure of the patient based on the patient specific data, and to determine a first FFR value within the anatomical structure of the patient based on the three-dimensional model and a physics-based model relating to the anatomical structure of the patient. The computer system is further configured to modify the three-dimensional model and to determine a second FFR value within the anatomical structure of the patient based on the modified three-dimensional model.
Granted U.S. Pat. No. 9,119,540 discloses an apparatus for non-invasively assessing a coronary artery disease based on medical image data. The apparatus comprises a means for generating an anatomical model of a coronary artery from medical image data and a means for estimating a velocity of blood in the coronary artery based on a spatio-temporal representation of contrast agent propagation in the medical image data. The apparatus further comprises a means for simulating blood flow in the anatomical model of the coronary artery using a computational fluid dynamics simulation that uses the estimated velocity of the blood in the coronary artery as a boundary condition.
Granted U.S. Pat. No. 9,757,073 discloses a system being adapted to determine an FFR value for a cardiac vessel having a stenosis based on extracted features and based on a learning model, wherein the extracted features have been extracted from segmented image data showing the cardiac vessel and the stenosis.
The article “CT Angiograhic Measurement of Vascular Blood Flow Velocity by Using Projection Data” by S. Prevrhal et al., Radiology, volume 261, number 3, pages 923 to 929 (2011) discloses a method for measuring a blood flow velocity by using projection data from CT scans.
Granted U.S. Pat. No. 9,867,584 discloses a system for determining a blood flow through coronary arteries. The system is adapted to generate a three-dimensional image data set of the coronary arteries and the myocardial muscle, to generate a three-dimensional marker data set of the myocardial muscle from a dual-energy or spectral three-dimensional data set obtained after administration of a marker, wherein the three-dimensional marker data set indicates the amount of the marker contained within voxels of the myocardial muscle, and to subdivide the myocardial muscle into myocardial muscle segments. The system is further adapted to determine which coronary artery supplies the respective myocardial muscle segment, to determine the volume of blood that flows into the respective myocardial muscle segments from the three-dimensional marker data set, and to determine the total volume of blood that flows into a coronary artery of interest by summing the volume of blood flowing into all myocardial muscle segments supplied by the coronary artery.
The FFR value of the coronary system is an important predictor of vascular health and typically measured invasively in a catheterization laboratory during percutaneous coronary interventions (PCIs). Alternatively, the fluid dynamics within the coronary system can be simulated based on a computed tomography (CT) image of the coronary system, in order to determine the FFR value. Determining the FFR value based on the simulation has the advantage that it can be determined non-invasively. However, the accuracy of the FFR value may be reduced in comparison to the invasively determined FFR value.